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134061163e
Fix UBSAN warnings that occur when using a system with 32 physical
cpu cores or more, or when the user defines a number of Ethernet
queues greater than or equal to FP_SB_MAX_E1x using the num_queues
module parameter.
Currently there is a read/write out of bounds that occurs on the array
"struct stats_query_entry query" present inside the "bnx2x_fw_stats_req"
struct in "drivers/net/ethernet/broadcom/bnx2x/bnx2x.h".
Looking at the definition of the "struct stats_query_entry query" array:
struct stats_query_entry query[FP_SB_MAX_E1x+
BNX2X_FIRST_QUEUE_QUERY_IDX];
FP_SB_MAX_E1x is defined as the maximum number of fast path interrupts and
has a value of 16, while BNX2X_FIRST_QUEUE_QUERY_IDX has a value of 3
meaning the array has a total size of 19.
Since accesses to "struct stats_query_entry query" are offset-ted by
BNX2X_FIRST_QUEUE_QUERY_IDX, that means that the total number of Ethernet
queues should not exceed FP_SB_MAX_E1x (16). However one of these queues
is reserved for FCOE and thus the number of Ethernet queues should be set
to [FP_SB_MAX_E1x -1] (15) if FCOE is enabled or [FP_SB_MAX_E1x] (16) if
it is not.
This is also described in a comment in the source code in
drivers/net/ethernet/broadcom/bnx2x/bnx2x.h just above the Macro definition
of FP_SB_MAX_E1x. Below is the part of this explanation that it important
for this patch
/*
* The total number of L2 queues, MSIX vectors and HW contexts (CIDs) is
* control by the number of fast-path status blocks supported by the
* device (HW/FW). Each fast-path status block (FP-SB) aka non-default
* status block represents an independent interrupts context that can
* serve a regular L2 networking queue. However special L2 queues such
* as the FCoE queue do not require a FP-SB and other components like
* the CNIC may consume FP-SB reducing the number of possible L2 queues
*
* If the maximum number of FP-SB available is X then:
* a. If CNIC is supported it consumes 1 FP-SB thus the max number of
* regular L2 queues is Y=X-1
* b. In MF mode the actual number of L2 queues is Y= (X-1/MF_factor)
* c. If the FCoE L2 queue is supported the actual number of L2 queues
* is Y+1
* d. The number of irqs (MSIX vectors) is either Y+1 (one extra for
* slow-path interrupts) or Y+2 if CNIC is supported (one additional
* FP interrupt context for the CNIC).
* e. The number of HW context (CID count) is always X or X+1 if FCoE
* L2 queue is supported. The cid for the FCoE L2 queue is always X.
*/
However this driver also supports NICs that use the E2 controller which can
handle more queues due to having more FP-SB represented by FP_SB_MAX_E2.
Looking at the commits when the E2 support was added, it was originally
using the E1x parameters: commit
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Linux kernel
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